The present invention generally relates to an apparatus useful for presenting samples to the exitation radiation of a fluorimeter and, in particular, relates to an apparatus including a linearly movable carrier.
Conventionally, a fluorimeter sampling apparatus includes a turntable having cuvette receptacles arranged on a circular line near the periphery thereof. To present samples, the turntable is rotated about its axis within a sample housing whereby the sample-containing cuvettes in the cuvette receptacles are individually and successively positioned in a measuring position. In this arrangement, the exitation radiation enters the housing along a radius of the turntable into the cuvette in the measuring position. The resultant fluorescence radiation exits in a direction normal with respect to the exitation radiation and is subsequently measured by a fluorimeter positioned external to the housing.
However, the above-described apparatus includes an inherent limitation on the number of samples which can be included on a single turntable. This limitation is significant as the number of samples to be measured increases, for example, in fluorescence-immuno assays, the processing of large numbers of samples is commonplace. The turntable apparatus is unsuited for such large numbers of samples since, if the radius is enlarged to accommodate more samples, the entire apparatus, including the housing, becomes quite bulky. Further, there is a practical limit to the number of samples usable on a given turntable due to the required geometrical arrangement of the optical paths within the housing.